github/esphome
2
0
Fork 0
mirror of https://github.com/esphome/esphome.git synced 2026-07-10 08:55:36 +00:00
Code Issues Packages Projects Releases Wiki Activity

[socket] Add LWIP_LOCK to UDP socket methods for RP2040 safety

Browse Source 
On RP2040, lwip callbacks run from a low-priority IRQ context and can
preempt main-loop code. All lwip API calls from the main loop must
hold the async_context lock (LWIP_LOCK) to prevent races on shared
lwip state (PCB lists, pbuf pools, IGMP groups).

The TCP implementation was already correct; the UDP methods were
missing the lock.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
J. Nick Koston
2026-03-14 15:57:57 -10:00
parent 1e935c128a
commit 519be06e73
1 changed files with 13 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
esphome/components/socket/lwip_raw_tcp_impl.cpp
+13 -2
View File
@@ -974,6 +974,7 @@ err_t LWIPRawListenImpl::accept_fn_(struct tcp_pcb *newpcb, err_t err) {
// ---- LWIPRawUDPImpl (send-only) methods ----
LWIPRawUDPImpl::LWIPRawUDPImpl(sa_family_t family) : family_(family) {
LWIP_LOCK();
#if LWIP_IPV6
this->pcb_ = udp_new_ip_type(family == AF_INET6 ? IPADDR_TYPE_ANY : IPADDR_TYPE_V4);
#else
@@ -982,6 +983,7 @@ LWIPRawUDPImpl::LWIPRawUDPImpl(sa_family_t family) : family_(family) {
}
LWIPRawUDPImpl::~LWIPRawUDPImpl() {
LWIP_LOCK();
if (this->pcb_ != nullptr) {
udp_remove(this->pcb_);
this->pcb_ = nullptr;
@@ -989,6 +991,7 @@ LWIPRawUDPImpl::~LWIPRawUDPImpl() {
}
int LWIPRawUDPImpl::bind_internal_(const struct sockaddr *name, socklen_t addrlen) {
LWIP_LOCK();
if (this->pcb_ == nullptr) {
errno = EBADF;
return -1;
@@ -1030,6 +1033,7 @@ int LWIPRawUDPImpl::bind_internal_(const struct sockaddr *name, socklen_t addrle
int LWIPRawUDPImpl::bind(const struct sockaddr *name, socklen_t addrlen) { return this->bind_internal_(name, addrlen); }
int LWIPRawUDPImpl::close() {
LWIP_LOCK();
if (this->pcb_ == nullptr) {
errno = EBADF;
return -1;
@@ -1081,6 +1085,7 @@ int LWIPRawUDPImpl::ip2sockaddr_(const ip_addr_t *ip, uint16_t port, struct sock
ssize_t LWIPRawUDPImpl::sendto(const void *buf, size_t len, int flags, const struct sockaddr *dest_addr,
socklen_t addrlen) {
LWIP_LOCK();
(void) flags; // Flags (MSG_DONTWAIT, etc.) are ignored; raw lwip is always non-blocking
if (this->pcb_ == nullptr) {
errno = EBADF;
@@ -1123,6 +1128,7 @@ ssize_t LWIPRawUDPImpl::sendto(const void *buf, size_t len, int flags, const str
}
int LWIPRawUDPImpl::setsockopt(int level, int optname, const void *optval, socklen_t optlen) {
LWIP_LOCK();
if (this->pcb_ == nullptr) {
errno = EBADF;
return -1;
@@ -1219,7 +1225,9 @@ LWIPRawUDPRecvImpl::~LWIPRawUDPRecvImpl() {
}
int LWIPRawUDPRecvImpl::close() {
// Unregister recv callback before removing pcb
LWIP_LOCK();
// Unregister recv callback before removing pcb — prevents new packets
// from being enqueued after we start flushing.
if (this->pcb_ != nullptr) {
udp_recv(this->pcb_, nullptr, nullptr);
}
@@ -1232,15 +1240,17 @@ int LWIPRawUDPRecvImpl::close() {
}
this->rx_read_idx_ = (this->rx_read_idx_ + 1) & UDP_RX_MASK;
}
// close() returns EBADF if already closed, which is fine from destructor
// Base close() acquires LWIP_LOCK again (recursive/reentrant on RP2040)
return LWIPRawUDPImpl::close();
}
int LWIPRawUDPRecvImpl::bind(const struct sockaddr *name, socklen_t addrlen) {
// bind_internal_ acquires LWIP_LOCK (recursive/reentrant on RP2040)
int ret = this->bind_internal_(name, addrlen);
if (ret != 0)
return ret;
// Register recv callback now that we're bound and ready to receive
LWIP_LOCK();
udp_recv(this->pcb_, LWIPRawUDPRecvImpl::s_recv_fn, this);
return 0;
}
@@ -1261,6 +1271,7 @@ ssize_t LWIPRawUDPRecvImpl::recvfrom(void *buf, size_t len, struct sockaddr *src
return -1;
}
LWIP_LOCK();
auto &pkt = this->rx_queue_[this->rx_read_idx_];
size_t pkt_len = pkt.pb->tot_len;
size_t copy_len = std::min(len, pkt_len);